Multi-Stage Process and Device for Treatment Heavy Marine Fuel Oil and Resultant Composition Including Ultrasound Promoted Desulfurization

ABSTRACT

A multi-stage process for reducing the environmental contaminants in an ISO8217 compliant Feedstock Heavy Marine Fuel Oil involving a core desulfurizing process and a ultrasound treatment process as either a pre-treating step or post-treating step to the core process. The Product Heavy Marine Fuel Oil complies with ISO 8217 for residual marine fuel oils and has a sulfur level has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05 mass % to 1.0 mass. A process plant for conducting the process is also disclosed.

BACKGROUND

There are two basic marine fuel types: distillate based marine fuel, also known as Marine Gas Oil (MGO) or Marine Diesel Oil (MDO); and residual based marine fuel, also known as heavy marine fuel oil (HMFO). Distillate based marine fuel both MGO and MDO, comprises petroleum middle distillate fractions separated from crude oil in a refinery via a distillation process. Gasoil (also known as medium diesel) is a petroleum middle distillate in boiling range and viscosity between kerosene (light distillate) and lubricating oil (heavy distillate) containing a mixture of C10 to C19 hydrocarbons. Gasoil (a heavy distillate) is used to heat homes and is used blending with lighter middle distillates as a fuel for heavy equipment such as cranes, bulldozers, generators, bobcats, tractors and combine harvesters. Generally maximizing middle distillate recovery from heavy distillates mixed with petroleum residues is the most economic use of these materials by refiners because they can crack gas oils into valuable gasoline and distillates in a fluid catalytic cracking (FCC) unit. Diesel oils for road use are very similar to gas oils with road use diesel containing predominantly contain a middle distillate mixture of C10 through C19 hydrocarbons, which include approximately 64% aliphatic hydrocarbons, 1-2% olefinic hydrocarbons, and 35% aromatic hydrocarbons. Distillate based marine fuels (MDO and MGO) are essentially road diesel or gas oil fractions blended with up to 15% residual process streams, and optionally up to 5% volume of polycyclic aromatic hydrocarbons (asphaltenes). The residual and asphaltene materials are blended into the middle distillate to form MDO and MGO as a way to both swell volume and productively use these low value materials.

Asphaltenes are large and complex polycyclic hydrocarbons with a propensity to form complex and waxy precipitates, especially in the presence of aliphatic (paraffinic) hydrocarbons that are the primary component of Marine Diesel. Once asphaltenes have precipitated out, they are notoriously difficult to re-dissolve and are described as fuel tank sludge in the marine shipping industry and marine bunker fueling industry. One of skill in the art will appreciate that mixing Marine Diesel with asphaltenes and process residues is limited by the compatibility of the materials and formation of asphaltene precipitates and the minimum Cetane number required for such fuels.

Residual based fuels or Heavy Marine Fuel Oil (HMFO) are used by large ocean-going ships as fuel for large two stroke diesel engines for over 50 years. HMFO is a blend of the residues generated throughout the crude oil refinery process. Typical refinery streams combined to from HMFO may include, but are not limited to: atmospheric tower bottoms (i.e. atmospheric residues), vacuum tower bottoms (i.e. vacuum residues) visbreaker residue, FCC Light Cycle Oil (LCO), FCC Heavy Cycle Oil (HCO) also known as FCC bottoms, FCC Slurry Oil, heavy gas oils and delayed cracker oil (DCO), deasphalted oils (DAO); heavy aromatic residues and mixtures of polycylic aromatic hydrocarbons, reclaimed land transport motor oils; pyrolysis oils and tars; aspahltene solids and tars; and minor portions (often less than 20% vol.) of middle distillate materials such as cutter oil, kerosene or diesel to achieve a desired viscosity. HMFO has a higher aromatic content (especially polynuclear aromatics and asphaltenes) than the marine distillate fuels noted above. The HMFO component mixture varies widely depending upon the crude slate (i.e. source of crude oil) processed by a refinery and the processes utilized within that refinery to extract the most value out of a barrel of crude oil. The HMFO is generally characterized as being highly viscous, high in sulfur and metal content (up to 5 wt %), and high in asphaltenes making HMFO the one product of the refining process that has historically had a per barrel value less than feedstock crude oil.

Industry statistics indicate that about 90% of the HMFO sold contains 3.5 weight % sulfur. With an estimated total worldwide consumption of HMFO of approximately 300 million tons per year, the annual production of sulfur dioxide by the shipping industry is estimated to be over 21 million tons per year. Emissions from HMFO burning in ships contribute significantly to both global marine air pollution and local marine air pollution levels.

The International Convention for the Prevention of Pollution from Ships, also known as the MARPOL convention or just MARPOL, as administered by the International Maritime Organization (IMO) was enacted to prevent marine pollution (i.e. marpol) from ships. In 1997, a new annex was added to the MARPOL convention; the Regulations for the Prevention of Air Pollution from Ships—Annex VI to minimize airborne emissions from ships (SO_(x), NO_(x), ODS, VOC) and their contribution to global air pollution. A revised Annex VI with tightened emissions limits was adopted in October 2008 and effective 1 Jul. 2010 (hereafter called Annex VI (revised) or simply Annex VI).

MARPOL Annex VI (revised) adopted in 2008 established a set of stringent air emissions limits for all vessel and designated Emission Control Areas (ECAs). The ECAs under MARPOL Annex VI are: i) Baltic Sea area—as defined in Annex I of MARPOL—SO_(x) only; ii) North Sea area—as defined in Annex V of MARPOL—SO_(x) only; iii) North American—as defined in Appendix VII of Annex VI of MARPOL—SO_(x), NO_(x) and PM; and, iv) United States Caribbean Sea area—as defined in Appendix VII of Annex VI of MARPOL—SO_(x), NO_(x) and PM.

Annex VI (revised) was codified in the United States by the Act to Prevent Pollution from Ships (APPS). Under the authority of APPS, the U.S. Environmental Protection Agency (the EPA), in consultation with the United States Coast Guard (USCG), promulgated regulations which incorporate by reference the full text of Annex VI. See 40 C.F.R. § 1043.100(a)(1). On Aug. 1, 2012 the maximum sulfur content of all marine fuel oils used onboard ships operating in US waters/ECA was reduced from 3.5% wt. to 1.00% wt. (10,000 ppm) and on Jan. 1, 2015 the maximum sulfur content of all marine fuel oils used in the North American ECA was lowered to 0.10% wt. (1,000 ppm). At the time of implementation, the United States government indicated that vessel operators must vigorously prepare to comply with the 0.10% wt. (1,000 ppm) US ECA marine fuel oil sulfur standard. To encourage compliance, the EPA and USCG refused to consider the cost of compliant low sulfur fuel oil to be a valid basis for claiming that compliant fuel oil was not available for purchase. For over five years there has been a very strong economic incentive to meet the marine industry demands for low sulfur HMFO, however technically viable solutions have not been realized and a premium price has been commanded by refiners to supply a low sulfur HMFO compliant with Annex VI sulfur emissions requirements in the ECA areas.

Since enactment in 2010, the global sulfur cap for HMFO outside of the ECA areas was set by Annex VI at 3.50% wt. effective 1 Jan. 2012; with a further reduction to 0.50% wt, effective 1 Jan. 2020. The global cap on sulfur content in HMFO has been the subject of much discussion in both the marine shipping and marine fuel bunkering industry. There has been and continues to be a very strong economic incentive to meet the international marine industry demands for low sulfur HMFO (i.e. HMFO with a sulfur content less than 0.50 wt. %. Notwithstanding this global demand, solutions for transforming high sulfur HMFO into low sulfur HMFO have not been realized or brought to market. There is an on-going and urgent demand for processes and methods for making a low sulfur HMFO compliant with MARPOL Annex VI emissions requirements.

Replacement of Heavy Marine Fuel Oil with Marine Gas Oil or Marine Diesel:

One primary solution to the demand for low sulfur HMFO to simply replace high sulfur HMFO with marine gas oil (MGO) or marine diesel (MDO). The first major difficulty is the constraint in global supply of middle distillate materials that make up 85-90% vol of MGO and MDO. It is reported that the effective spare capacity to produce MGO is less than 100 million metric tons per year resulting in an annual shortfall in marine fuel of over 200 million metric tons per year. Refiners not only lack the capacity to increase the production of MGO, but they have no economic motivation because higher value and higher margins can be obtained from using middle distillate fractions for low sulfur diesel fuel for land-based transportation systems (i.e. trucks, trains, mass transit systems, heavy construction equipment, etc.).

Blending:

Another primary solution is the blending of high sulfur HMFO with lower sulfur containing fuels such as MGO or MDO low sulfur marine diesel (0.1% wt. sulfur) to achieve a Product HMFO with a sulfur content of 0.5% wt. In a straight blending approach (based on linear blending) every 1 ton of high sulfur HSFO (3.5% sulfur) requires 7.5 tons of MGO or MDO material with 0.1% wt. S to achieve a sulfur level of 0.5% wt. HMFO. One of skill in the art of fuel blending will immediately understand that blending hurts key properties of the HMFO, specifically lubricity, fuel density, CCAI, viscosity, flash point and other important physical bulk properties. Blending a mostly paraffinic-type distillate fuel (MGO or MDO) with a HMFO having a high poly aromatic content often correlates with poor solubility of asphaltenes. A blended fuel is likely to result in the precipitation of asphaltenes and/or waxing out of highly paraffinic materials from the distillate material forming an intractable fuel tank sludge. Fuel tank sludge causes clogging of filters and separators, transfer pumps and lines, build-up of sludge in storage tanks, sticking of fuel injection pumps, and plugged fuel nozzles. Such a risk to the primary propulsion system is not acceptable for a ship in the open ocean.

It should further be noted that blending of HMFO with marine distillate products (MGO or MDO) is not economically viable. A blender will be taking a high value product (0.1% S marine gas oil (MGO) or marine diesel (MDO)) and blending it 7.5 to 1 with a low value high sulfur HMFO to create a final IMO/MARPOL compliant HMFO (i.e. 0.5% wt. S Low Sulfur Heavy Marine Fuel Oil—LSHMFO) which will sell at a discount to the value of the principle ingredient (i.e. MGO or MDO).

Processing of Residual Oils.

For the past several decades, the focus of refining industry research efforts related to the processing of heavy oils (crude oils, distressed oils, or residual oils) has been on upgrading the properties of these low value refinery process oils to create middle distillate and lighter oils with greater value. The challenge has been that crude oil, distressed oil and residues contain high levels of sulfur, nitrogen, phosphorous, metals (especially vanadium and nickel); asphaltenes and exhibit a propensity to form carbon or coke on the catalyst. The sulfur and nitrogen molecules are highly refractory and aromatically stable and difficult and expensive to crack or remove. Vanadium and nickel porphyrins and other metal organic compounds are responsible for catalyst contamination and corrosion problems in the refinery. The sulfur, nitrogen, and phosphorous, must be removed because they are well-known poisons for the precious metal (platinum and palladium) catalysts utilized in the processes downstream of the atmospheric or vacuum distillation towers.

The difficulties treating atmospheric or vacuum residual streams has been known for many years and has been the subject of considerable research and investigation. Numerous residue-oil conversion processes have been developed in which the goals are same: 1) create a more valuable, preferably middle distillate range hydrocarbons; and 2) concentrate the contaminates such as sulfur, nitrogen, phosphorous, metals and asphaltenes into a form (coke, heavy coker residue, FCC slurry oil) for removal from the refinery stream. Well known and accepted practice in the refining industry is to increase the reaction severity (elevated temperature and pressure) to produce hydrocarbon products that are lighter and more purified, increase catalyst life times and remove sulfur, nitrogen, phosphorous, metals and asphaltenes from the refinery stream.

In summary, since the announcement of the MARPOL Annex VI standards reducing the global levels of sulfur in HMFO, refiners of crude oil have had modest success in their technical efforts to create a process for the production of a low sulfur substitute for high sulfur HMFO. Despite the strong governmental and economic incentives and needs of the international marine shipping industry, refiners have little economic reason to address the removal of environmental contaminates from high sulfur HMFOs. The global refining industry has been focused upon generating greater value from each barrel of oil by creating middle distillate hydrocarbons (i.e. diesel) and concentrating the environmental contaminates into increasingly lower value streams (i.e. residues) and products (petroleum coke, HMFO). Shipping companies have focused on short term solutions, such as the installation of scrubbing units, or adopting the limited use of more expensive low sulfur marine diesel and marine gas oils as a substitute for HMFO. On the open seas, most if not all major shipping companies continue to utilize the most economically viable fuel, that is HMFO. There remains a long standing and unmet need for processes and devices that remove the environmental contaminants (i.e. sulfur, nitrogen, phosphorous, metals especially vanadium and nickel) from HMFO without altering the qualities and properties that make HMFO the most economic and practical means of powering ocean going vessels.

SUMMARY

It is a general objective to reduce the environmental contaminates from a Heavy Marine Fuel Oil (HMFO) in a multi stage process including the use of ultrasonic desulfurization, that minimizes the changes in the desirable properties of the HMFO and minimizes the unnecessary production of by-product hydrocarbons (i.e. light hydrocarbons having C₁-C₄ and wild naptha (C₅-C₂₀)).

A first aspect and illustrative embodiment encompasses a multi-stage process for reducing the environmental contaminants in a Feedstock Heavy Marine Fuel Oil, the process involving: contacting a Feedstock Heavy Marine Fuel Oil with a ultrasonic desulfurization process to give a pre-treated Feedstock Heavy Marine Fuel Oil; mixing a quantity of the pre-treated Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more catalysts under desulfurizing conditions to form a Process Mixture from the Feedstock Mixture; receiving the Process Mixture and separating the Product Heavy Marine Fuel Oil liquid components of the Process Mixture from the gaseous components and by-product hydrocarbon components of the Process Mixture and, discharging the Product Heavy Marine Fuel Oil.

A second aspect and illustrative embodiment encompasses a process for reducing the environmental contaminants in HMFO, in which the process involves: mixing a quantity of Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more catalysts under desulfurizing conditions to form a Process Mixture from the Feedstock Mixture; receiving the Process Mixture and separating the liquid components of the Process Mixture from the bulk gaseous components of the Process Mixture; receiving the liquid components and contacting the liquid components with a ultrasonic desulfurization process; then separating any residual gaseous components and by-product hydrocarbon components from the Product Heavy Marine Fuel Oil; and, discharging the Product Heavy Marine Fuel Oil.

A third and fourth aspect and illustrative embodiment encompasses a device for reducing environmental contaminants in a Feedstock HMFO and producing a Product HMFO. The illustrative devices embody the above illustrative processes on a commercial scale.

A fifth aspect and illustrative embodiment encompasses a Heavy Marine Fuel Oil composition resulting from the above illustrative processes.

DESCRIPTION OF DRAWINGS

FIG. 1 is a process block flow diagram of an illustrative core process to produce Product HMFO.

FIG. 2 is a process flow diagram of a multistage process utilizing an ultrasonic desulfurization process to pre-treat the feedstock HMFO and a subsequent core process to produce Product HMFO.

FIG. 3 is a process flow diagram of a multi-stage process utilizing a core process followed by a subsequent ultrasonic desulfurization process to produce Product HMFO.

FIG. 4 is a basic schematic diagram of a plant to produce Product HMFO utilizing a combination of an ultrasonic desulfurization process to pre-treat the feedstock HMFO and a subsequent core process to produce Product HMFO.

FIG. 5 is a basic schematic diagram of a plant to produce Product HMFO utilizing a combination of a core process and ultrasonic desulfurization process to produce Product HMFO.

DETAILED DESCRIPTION

The inventive concepts as described herein utilize terms that should be well known to one of skill in the art, however certain terms are utilized having a specific intended meaning and these terms are defined below:

Heavy Marine Fuel Oil (HMFO) is a petroleum product fuel compliant with the ISO 8217 (2017) standards for the bulk properties of residual marine fuels except for the concentration levels of the Environmental Contaminates.

Environmental Contaminates are organic and inorganic components of HMFO that result in the formation of SO_(x), NO_(x) and particulate materials upon combustion.

Feedstock HMFO is a petroleum product fuel compliant with the ISO 8217 (2017) standards for the bulk properties of residual marine fuels except for the concentration of Environmental Contaminates, preferably the Feedstock HMFO has a sulfur content greater than the global MARPOL standard of 0.5% wt. sulfur, and preferably and has a sulfur content (ISO 14596 or ISO 8754) between the range of 5.0% wt. to 1.0% wt.

Product HMFO is a petroleum product fuel compliant with the ISO 8217 (2017) standards for the bulk properties of residual marine fuels and achieves a sulfur content lower than the global MARPOL standard of 0.5% wt. sulfur (ISO 14596 or ISO 8754), and preferably a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. to 1.0% wt.

Activating Gas: is a mixture of gases utilized in the process combined with the catalyst to remove the environmental contaminates from the Feedstock HMFO.

Fluid communication: is the capability to transfer fluids (either liquid, gas or combinations thereof, which might have suspended solids) from a first vessel or location to a second vessel or location, this may encompass connections made by pipes (also called a line), spools, valves, intermediate holding tanks or surge tanks (also called a drum).

Merchantable quality: is a level of quality for a residual marine fuel oil so the fuel is fit for the ordinary purpose it should serve (i.e. serve as a residual fuel source for a marine ship) and can be commercially sold as and is fungible with heavy or residual marine bunker fuel.

Bbl or bbl: is a standard volumetric measure for oil; 1 bbl=0.1589873 m³; or 1 bbl=158.9873 liters; or 1 bbl=42.00 US liquid gallons.

Bpd: is an abbreviation for Bbl per day.

SCF: is an abbreviation for standard cubic foot of a gas; a standard cubic foot (at 14.73 psi and 60° F.) equals 0.0283058557 standard cubic meters (at 101.325 kPa and 15° C.).

The inventive concepts are illustrated in more detail in this description referring to the drawings, in which FIG. 1 shows the generalized block process flows for a core process of reducing the environmental contaminates in a Feedstock HMFO and producing a Product HMFO. A predetermined volume of Feedstock HMFO (2) is mixed with a predetermined quantity of Activating Gas (4) to give a Feedstock Mixture. The Feedstock HMFO utilized generally complies with the bulk physical and certain key chemical properties for a residual marine fuel oil otherwise compliant with ISO 8217 (2017) exclusive of the Environmental Contaminates. More particularly, when the Environmental Contaminate is sulfur, the concentration of sulfur in the Feedstock HMFO may be between the range of 5.0% wt. to 1.0% wt. The Feedstock HMFO should have bulk physical properties required of an ISO 8217 (2017) compliant HMFO of: a maximum of kinematic viscosity at 50 C (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a maximum of density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment-aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue-micro method (ISO 10370) less than 20.00 mass % and preferably also a aluminum plus silicon (ISO 10478) content less than 60 mg/kg. Environmental Contaminates other than sulfur that may be present in the Feedstock HMFO over the ISO requirements may include vanadium, nickel, iron, aluminum and silicon substantially reduced by the process of the present invention. However, one of skill in the art will appreciate that the vanadium content serves as a general indicator of these other Environmental Contaminates. In one preferred embodiment the vanadium content is ISO compliant so the Feedstock MHFO has a maximum vanadium content (ISO 14597) between the range from 350 mg/kg to 450 ppm mg/kg.

As for the properties of the Activating Gas, the Activating Gas should be selected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseous water, and methane. The mixture of gases within the Activating Gas should have an ideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of the total pressure of the Activating Gas mixture (P) and more preferably wherein the Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 90% of the total pressure of the Activating Gas mixture (P). It will be appreciated by one of skill in the art that the molar content of the Activating Gas is another criterion the Activating Gas should have a hydrogen mole fraction in the range between 80% and 100% of the total moles of Activating Gas mixture.

The Feedstock Mixture (i.e. mixture of Feedstock HMFO and Activating Gas) is brought up to the process conditions of temperature and pressure and introduced into a first vessel, preferably a reactor vessel, so the Feedstock Mixture is then contacted with one or more catalysts (8) to form a Process Mixture from the Feedstock Mixture.

The core process reactive conditions are selected so the ratio of the quantity of the Activating Gas to the quantity of Feedstock HMFO is 250 scf gas/bbl of Feedstock HMFO to 10,000 scf gas/bbl of Feedstock HMFO; and preferably between 2000 scf gas/bbl of Feedstock HMFO 1 to 5000 scf gas/bbl of Feedstock HMFO more preferably between 2500 scf gas/bbl of Feedstock HMFO to 4500 scf gas/bbl of Feedstock HMFO. The process conditions are selected so the total pressure in the first vessel is between of 250 psig and 3000 psig; preferably between 1000 psig and 2500 psig, and more preferably between 1500 psig and 2200 psig. The process conditions are selected so the indicated temperature within the first vessel is between of 500° F. to 900° F., preferably between 650° F. and 850° F. and more preferably between 680° F. and 800° F. The process conditions are selected so the liquid hourly space velocity within the first vessel is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³ catalyst; preferably between 0.08 oil/hour/m³ catalyst and 0.5 oil/hour/m³ catalyst; and more preferably between 0.1 oil/hour/m³ catalyst and 0.3 oil/hour/m³ catalyst to achieve deep desulfurization with product sulfur levels below 0.1 ppmw.

One of skill in the art will appreciate that the core process reactive conditions are determined to consider the hydraulic capacity of the unit. Exemplary hydraulic capacity for the treatment unit may be between 100 bbl of Feedstock HMFO/day and 100,000 bbl of Feedstock HMFO/day, preferably between 1000 bbl of Feedstock HMFO/day and 60,000 bbl of Feedstock HMFO/day, more preferably between 5,000 bbl of Feedstock HMFO/day and 45,000 bbl of Feedstock HMFO/day, and even more preferably between 10,000 bbl of Feedstock HMFO/day and 30,000 bbl of Feedstock HMFO/day.

The core process may utilize one or more catalyst materials selected from the group consisting of: an ebulliated bed supported transition metal heterogeneous catalyst, a fixed bed supported transition metal heterogeneous catalyst, and a combination of ebulliated bed supported transition metal heterogeneous catalysts and fixed bed supported transition metal heterogeneous catalysts. One of skill in the art will appreciate that a fixed bed supported transition metal heterogeneous catalyst will be the technically easiest to implement and is preferred. The transition metal heterogeneous catalyst comprises a porous inorganic oxide catalyst carrier and a transition metal catalyst. The porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier. The transition metal component of the catalyst is one or more metals selected from the group consisting of group 6, 8, 9 and 10 of the Periodic Table. In a preferred and illustrative embodiment, the transition metal heterogeneous catalyst is a porous inorganic oxide catalyst carrier and a transition metal catalyst, in which the preferred porous inorganic oxide catalyst carrier is alumina and the preferred transition metal catalyst is Ni—Mo, Co—Mo, Ni—W or Ni—Co—Mo.

The Process Mixture (10) in this core process is removed from the first vessel (8) and from being in contact with the one or more catalyst and is sent via fluid communication to a second vessel (12), preferably a gas-liquid separator or hot separators and cold separators, for separating the liquid components (14) of the Process Mixture from the bulk gaseous components (16) of the Process Mixture. The gaseous components (16) are treated beyond the battery limits of the immediate process. Such gaseous components may include a mixture of Activating Gas components and lighter hydrocarbons (mostly methane, ethane and propane but some wild naphtha) that may have been formed as part of the by-product hydrocarbons from the process.

The Liquid Components (16) in this core process are sent via fluid communication to a third vessel (18), preferably a fuel oil product stripper system, for separating any residual gaseous components (20) and by-product hydrocarbon components (22) from the Product HMFO (24). The residual gaseous components (20) may be a mixture of gases selected from the group consisting of: nitrogen, hydrogen, carbon dioxide, hydrogen sulfide, gaseous water, C₁-C₅ hydrocarbons. This residual gas is treated outside of the battery limits of the immediate process, combined with other gaseous components (16) removed from the Process Mixture (10) in the second vessel (12). The liquid by-product hydrocarbon component, which are condensable hydrocarbons formed in the process (22) may be a mixture selected from the group consisting of C₅-C₂₀ hydrocarbons (wild naphtha) (naphtha-diesel) and other condensable light liquid (C₃-C₈) hydrocarbons that can be utilized as part of the motor fuel blending pool or sold as gasoline and diesel blending components on the open market. These liquid by-product hydrocarbons should be less than 15% wt., preferably less than 5% wt. and more preferably less than 3% wt. of the overall process mass balance.

The Product HMFO (24) resulting from the core process is discharged via fluid communication into storage tanks beyond the battery limits of the immediate process. The Product HMFO complies with ISO 8217 (2017) and has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05 mass % to 1.0 mass % preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.05 mass % ppm and 0.7 mass % and more preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.1 mass % and 0.5 mass %. The vanadium content of the Product HMFO is also ISO compliant with a maximum vanadium content (ISO 14597) between the range from 350 mg/kg to 450 ppm mg/kg, preferably a vanadium content (ISO 14597) between the range of 200 mg/kg and 300 mg/kg and more preferably a vanadium content (ISO 14597) less than 50 mg/kg.

The Product HFMO should have bulk physical properties of: a kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment-aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue-micro method (ISO 10370) less than 20.00 mass % and also preferably a maximum aluminum plus silicon (ISO 10478) content of 60 mg/kg.

The Product HMFO will have a sulfur content (ISO 14596 or ISO 8754) between 1% and 20% of the maximum sulfur content of the Feedstock Heavy Marine Fuel Oil. That is the sulfur content of the Product will be reduced by about 80% or greater when compared to the Feedstock HMFO. Similarly, the vanadium content (ISO 14597) of the Product Heavy Marine Fuel Oil is between 1% and 20% of the maximum vanadium content of the Feedstock Heavy Marine Fuel Oil. One of skill in the art will appreciate that the above data indicates a substantial reduction in sulfur and vanadium content indicate a process having achieved a substantial reduction in the Environmental Contaminates from the Feedstock HMFO while maintaining the desirable properties of an ISO compliant HMFO.

As a side note, the residual gaseous component is a mixture of gases selected from the group consisting of: nitrogen, hydrogen, carbon dioxide, hydrogen sulfide, gaseous water, C₁-C₅ hydrocarbons. An amine scrubber will effectively remove the hydrogen sulfide content which can then be processed using technologies and processes well known to one of skill in the art. In one preferable illustrative embodiment, the hydrogen sulfide is converted into elemental sulfur using the well-known Claus process. An alternative embodiment utilizes a proprietary process for conversion of the Hydrogen sulfide to hydrosulfuric acid. Either way, the sulfur is removed from entering the environment prior to combusting the HMFO in a ships engine. The cleaned gas can be vented, flared or more preferably recycled back for use as Activating Gas.

Ultrasound Treatment Process: It will be appreciated by one of skill in the art, that the conditions utilized in the core process have been intentionally selected to minimize cracking of hydrocarbons and remove significant levels of sulfur from the Feedstock HMFO. However, one of skill in the art will also appreciate there may be certain compounds present in the Feedstock HMFO removal of which would have a positive impact upon the properties of the Product HMFO. These processes and systems must achieve this without substantially altering the desirable bulk properties (i.e. compliance with ISO 8217 (2017) exclusive of sulfur content) of the Product HMFO.

The ultrasound utilized in the present illustrative embodiment may be a conventional industrial high energy transducer for chemical reactions such as those disclosed in U.S. Pat. Nos. 6,897,628; 7,712,353; 7,928,614; 7,790,002; 7,879,200; US20090038932. Alternatively a loop type ultrasound generator such as that disclosed in U.S. Pat. No. 7,275,440 (the contents of which are incorporated herein by reference) may be used. When water or supercritical water is present with the HMFO the relative amounts of the oil and aqueous phases in the emulsion may vary usually however, best results will be achieved when the volume ratio of organic phase to aqueous phase is from about 25:1 to about 1:5, preferably from about 20:1 to about 1:2, and most preferably from about 12:1 to about 1:1. A ratio presently preferred is 10:1. An optional oxidizing agent, such as hydroperoxide or another water soluble peroxide or oxidizing agent may be present in the aqueous solution. When a hydroperoxide is present, the amount can vary. Usually best results will be achieved with a hydroperoxide concentration of from about 10 ppm to about 100 ppm by weight, and preferably from about 15 ppm to about 50 ppm by weight, of the aqueous solution. In certain embodiments of this invention, a surface active agent or other emulsion stabilizer is included to stabilize the emulsion as the organic and aqueous phases are being prepared for the ultrasound exposure. A further optional component may be a catalytic metal. Usually water will not be present when a metallic catalyst is utilized. Examples are transition metal catalysts, preferably metals having atomic numbers of 21 through 29, 39 through 47, and 57 through 79. Particularly preferred metals from this group are nickel, silver, tungsten (and tungstates), and combinations thereof. In certain systems within the scope of this invention, Fenton catalysts (ferrous salts) and metal ion catalysts in general such as iron (II), iron (III), copper (I), copper (II), chromium (III), chromium (VI), molybdenum, tungsten, and vanadium ions, are useful. Of these, iron (II), iron III), copper II), and tungsten catalysts are preferred. For some systems, Fenton-type catalysts are preferred, while for others, tungstates are preferred. Tungstates include tungstic acid, substituted tungstic acids such as phosphotungstic acid, and metal tungstates. The metallic catalyst when present will be used in a catalytically effective amount, which means any amount that will enhance the progress of the reactions by which the HMFO components are treated. The catalyst may be present as metal particles, pellets, screens, or any form with high surface area and can be retained in the ultrasound chamber.

Ultrasound consists of soundlike waves at a frequency above the range of normal human hearing, i.e., above 20 kHz (20,000 cycles per second). Ultrasonic energy with frequencies as high as 10 gigahertz (10,000,000,000 cycles per second) has been generated, but for this invention, useful results will be achieved with frequencies within the range of from about 10 kHz to about 100 MHz, and preferably within the range of from about 10 kHz to about 30 MHz. Ultrasonic waves can be generated from mechanical, electrical, electromagnetic, or thermal energy sources. The intensity of the sonic energy may also vary widely. For this invention, best results will generally be achieved with an intensity ranging from about 30 watts/cm2 to about 300 watts/cm2, or preferably from about 50 watts/cm2 to about 100 watts/cm2. The typical electromagnetic source is a magnetostrictive transducer which converts magnetic energy into ultrasonic energy by applying a strong alternating magnetic field to certain metals, alloys and ferrites. The typical electrical source is a piezoelectric transducer, which uses natural or synthetic single crystals (such as quartz) or ceramics (such as barium titanate or lead zirconate) and applies an alternating electrical voltage across opposite faces of the crystal or ceramic to cause an alternating expansion and contraction of crystal or ceramic at the impressed frequency. Ultrasound has wide applications in such areas as cleaning for the electronics, automotive, aircraft, and precision instruments industries, flow metering for closed systems such as coolants in nuclear power plants or for blood flow in the vascular system, materials testing, machining, soldering and welding, electronics, agriculture, oceanography, and medical imaging. The methods of producing and applying ultrasonic energy, and commercial suppliers of ultrasound equipment, are well known among those skilled in ultrasound technology. In the preferred practice of the invention, ultrasound is administered by used of an ultrasonic transducer and an ultrasonic horn.

The exposure time of the HMFO to ultrasound is not critical to the practice or the success of the invention, and the optimal exposure time will vary according to the material being treated. However, effective and useful results can be achieved with a relatively short exposure time. Best results will generally be obtained with exposure times ranging from about 8 seconds to about 150 seconds.

In US20060180500, the ultrasonic treatment may be combined with a microwave treatment, such as that disclosed in co-pending application entitled “Multi-Stage Process and Device for Treatment Heavy Marine Fuel Oil and Resultant Composition including Microwave Promoted Desulfurization” which is co-owned herewith.

The Ultrasound Treatment Unit (UTU) comprises a conventional reactor equipped with ultrasonic transducers as a source of high energy ultrasound. Construction of this unit, which may operate at relatively low pressures lower than 2 MPa, and temperatures equal to or lower than 300° C., adopted in this process would not present technical difficulties for an experienced technician in this field. For example see the reactors disclosed in U.S. Pat. Nos. 4,168,295; 7,275,440 or 9,339,785 as an illustrative examples of ultrasonic energy based reactors that allow for elevated temperature, pressure, presence of catalytic materials, and continuous flow of feedstock materials (i.e. Feedstock HMFO and optionally hydrogen).

Generally, the ultrasonic treatment process contemplated within the scope of the present invention involves placing the referred Feedstock HMFO or Product HMFO into contact in batches or continually with a fixed or slurry bed subject to the action of ultrasonic energy. The bed comprises a heterogeneous catalytic material, such as a catalyst from a hydrotreatment unit. The load input temperature ranges between 25° C. and 300° C., preferably at a temperature ranging between 30° C. and 260° C. The pressure of the system is not critical and may be adjusted in such a way that prior to treatment it is equal to or lower than the pressure of the previous unit and after treatment the current is at the normal pressure of this system. Spatial velocity ranges from between 0.10 h⁻¹ and 10 h⁻¹, preferably within a range of between 0.2 h⁻¹ and 6 h⁻¹.

An advantage of the ultrasonic treatment process is that it operates at relatively low temperature and pressure preserving the desirable properties (such a lubricity, energy density, and aromaticity) of the ISO 8217 (2017) compliant HMFO.

In this description, items already described above as part of the core process have retained the same numbering and designation for ease of description. As show in FIG. 2, a UTU 3 can be utilized to pre-treat the Feedstock HMFO prior to mixing with the Activating Gas 4 as part of the core process disclosed above. While simplistically represented in this drawing, the UTU 3 may be multiple parallel or in series UTU's however the UTU may be as simple as a single reactor vessel in which the HMFO is exposed to Ultrasound energy in the presence of catalyst. While a single a fixed bed, flow through/contact vessel may be used, it may be advantageous and it is preferable to have multiple contact vessels in parallel with each other to allow for one unit to be active while a second or third unit are being reloaded. Such an arrangement involving multiple parallel contact vessels with pipes/switching valves, etc. . . . is well within the abilities of one of skill in the art of refinery process design and operation.

An alternative illustrative embodiment is shown in FIG. 3 in which a UTU 17 is utilized after the core sulfur removal process step, but prior to the separation of the Product HMFO 24 from any Residual Gas 20 and By-Product 22 (i.e. mostly C₁-C₄ hydrocarbons, and wild naptha). In such a configuration the UTU effectively acts as a polishing unit to remove sulfur containing complex molecules present in the HMFO not removed under the conditions in the core process step. As with the pre-treatment UTU described above, the conditions in this post-treatment UTU are moderate. It is believed that because this step of the process will be conducted under very modest conditions (i.e. moderately elevated temperatures sufficient to make the HMFO liquid-like in this process) that will have minimal to no adverse impact upon the bulk physical properties of the product HMFO. In this way one may achieve a level of desulfurization reduction for a HMFO not achieved otherwise while minimizing the cracking of hydrocarbons and maintaining the other desirable bulk properties of the HMFO.

Product HMFO The Product HFMO resulting from the disclosed illustrative process is of merchantable quality for sale and use as a heavy marine fuel oil (also known as a residual marine fuel oil or heavy bunker fuel) and exhibits the bulk physical properties required for the Product HMFO to be an ISO compliant (i.e. ISO 8217 (2017)) residual marine fuel oil. The Product HMFO should exhibit the bulk properties of: a maximum of kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a maximum of density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment-aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue-micro method (ISO 10370) less than 20.00 mass % and preferably a maximum aluminum plus silicon (ISO 10478) content less than 60 mg/kg.

The Product HMFO has a sulfur content (ISO 14596 or ISO 8754) less than 0.5 wt % and preferably less than 0.1% wt. and complies with the IMO Annex VI (revised) requirements for a low sulfur and preferably an ultra-low sulfur HMFO. That is the sulfur content of the Product HMFO has been reduced by about 80% or greater when compared to the Feedstock HMFO. Similarly, the vanadium content (ISO 14597) of the Product Heavy Marine Fuel Oil is less than 20% and more preferably less than 5% of the maximum vanadium content of the Feedstock Heavy Marine Fuel Oil. One of skill in the art will appreciate that a substantial reduction in sulfur and vanadium content of the Feedstock HMFO indicates a process having achieved a substantial reduction in the Environmental Contaminates from the Feedstock HMFO; of equal importance is this has been achieved while maintaining the desirable properties of an ISO 8217 (2017) compliant HMFO.

The Product HMFO not only complies with ISO 8217 (2017) (and is merchantable as a residual marine fuel oil or bunker fuel), the Product HMFO has a maximum sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. to 1.0% wt. preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.05% wt. ppm and 0.5% wt. and more preferably a sulfur content (ISO 14596 or ISO 8754) between the range of 0.1% wt. and 0.5% wt. The vanadium content of the Product HMFO is well within the maximum vanadium content (ISO 14597) required for an ISO 8217 (2017) residual marine fuel oil exhibiting a vanadium content lower than 450 ppm mg/kg, preferably a vanadium content (ISO 14597) lower than 300 mg/kg and more preferably a vanadium content (ISO 14597) less than 50 mg/kg.

One knowledgeable in the art of marine fuel blending, bunker fuel formulations and the fuel logistical requirements for marine shipping fuels will readily appreciate that without further compositional changes or blending, the Product HMFO can be sold and used as a low sulfur MARPOL Annex VI compliant heavy (residual) marine fuel oil that is a direct substitute for the high sulfur heavy (residual) marine fuel oil or heavy bunker fuel currently in use. One illustrative embodiment is an ISO 8217 (2017) compliant low sulfur heavy marine fuel oil comprising (and preferably consisting essentially of) a hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil, wherein the sulfur levels of the hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil is greater than 0.5% wt. and wherein the sulfur levels of the ISO 8217 (2017) compliant low sulfur heavy marine fuel oil is less than 0.5% wt. Another illustrative embodiment is an ISO 8217 (2017) compliant ultra-low sulfur heavy marine fuel oil comprising (and preferably consisting essentially of) a 100% hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil, wherein the sulfur levels of the hydroprocessed ISO 8217 (2017) compliant high sulfur heavy marine fuel oil is greater than 0.5% wt. and wherein the sulfur levels of the ISO 8217 (2017) compliant low sulfur heavy marine fuel oil is less than 0.1% wt.

Because of the present invention, multiple economic and logistical benefits to the bunkering and marine shipping industries can be realized. The benefits include minimal changes to the existing heavy marine fuel bunkering infrastructure (storage and transferring systems); minimal changes to shipboard systems are needed to comply with emissions requirements of MARPOL Annex VI (revised); no additional training or certifications for crew members will be needed, amongst the realizable benefits. Refiners will also realize multiple economic and logistical benefits, including: no need to alter or rebalance the refinery operations, crude slates and product streams to meet a new market demand for low sulfur or ultralow sulfur HMFO; no additional units are needed in the refinery with additional hydrogen or sulfur capacity because the illustrative process can be conducted as a stand-alone unit; refinery operations can remain focused on those products that create the greatest value from the crude oil received (i.e. production of petrochemicals, gasoline and distillate (diesel); refiners can continue using the existing slates of crude oils without having to switch to sweeter or lighter crudes to meet the environmental requirements for HMFO products.

Heavy Marine Fuel Composition One aspect of the present inventive concept is a fuel composition comprising, but preferably consisting essentially of, the Product HMFO resulting from the processes disclosed, and may optionally include Diluent Materials. The bulk properties of the Product HMFO itself complies with ISO 8217 (2017) and meets the global IMO Annex VI requirements for maximum sulfur content (ISO 14596 or ISO 8754). If ultra low levels of sulfur are desired, the process of the present invention achieves this and one of skill in the art of marine fuel blending will appreciate that a low sulfur or ultra-low sulfur Product HMFO can be utilized as a primary blending stock to form a global IMO Annex VI compliant low sulfur Heavy Marine Fuel Composition. Such a low sulfur Heavy Marine Fuel Composition will comprise (and preferably consist essentially of): a) the Product HMFO and b) Diluent Materials. In one embodiment, the majority of the volume of the Heavy Marine Fuel Composition is the Product HMFO with the balance of materials being Diluent Materials. Preferably, the Heavy Marine Fuel Composition is at least 75% by volume, preferably at least 80% by volume, more preferably at least 90% by volume, and furthermore preferably at least 95% by volume Product HMFO with the balance being Diluent Materials.

Diluent Materials may be hydrocarbon or non-hydrocarbon based materials mixed into or combined with or added to, or solid particle materials suspended in, the Product HMFO. The Diluent Materials may intentionally or unintentionally alter the composition of the Product HMFO but not so the resulting mixture violates the ISO 8217 (2017) standards for the properties of residual marine fuels or fails to have a sulfur content lower than the global MARPOL standard of 0.5% wt. sulfur (ISO 14596 or ISO 8754). Examples of Diluent Materials considered hydrocarbon based materials include: Feedstock HMFO (i.e. high sulfur HMFO); distillate based fuels such as road diesel, gas oil, MGO or MDO; cutter oil (which is used in formulating residual marine fuel oils); renewable oils and fuels such as biodiesel, methanol, ethanol; synthetic hydrocarbons and oils based on gas to liquids technology such as Fischer-Tropsch derived oils, synthetic oils such as those based on polyethylene, polypropylene, dimer, trimer and poly butylene; refinery residues or other hydrocarbon oils such as atmospheric residue, vacuum residue, fluid catalytic cracker (FCC) slurry oil, FCC cycle oil, pyrolysis gasoil, cracked light gas oil (CLGO), cracked heavy gas oil (CHGO), light cycle oil (LCO), heavy cycle oil (HCO), thermally cracked residue, coker heavy distillate, bitumen, de-asphalted heavy oil, visbreaker residue, slop oils, asphaltinic oils; used or recycled motor oils; lube oil aromatic extracts and crude oils such as heavy crude oil, distressed crude oils and similar materials that might otherwise be sent to a hydrocracker or diverted into the blending pool for a prior art high sulfur heavy (residual) marine fuel oil. Examples of Diluent Materials considered non-hydrocarbon based materials include: residual water (i.e. water absorbed from the humidity in the air or water that is miscible or solubilized, sometimes as microemulsions, into the hydrocarbons of the Product HMFO), fuel additives which can include, but are not limited to detergents, viscosity modifiers, pour point depressants, lubricity modifiers, de-hazers (e.g. alkoxylated phenol formaldehyde polymers), antifoaming agents (e.g. polyether modified polysiloxanes); ignition improvers; anti rust agents (e.g. succinic acid ester derivatives); corrosion inhibitors; anti-wear additives, anti-oxidants (e.g. phenolic compounds and derivatives), coating agents and surface modifiers, metal deactivators, static dissipating agents, ionic and nonionic surfactants, stabilizers, cosmetic colorants and odorants and mixtures of these. A third group of Diluent Materials may include suspended solids or fine particulate materials that are present because of the handling, storage and transport of the Product HMFO or the Heavy Marine Fuel Composition, including but not limited to: carbon or hydrocarbon solids (e.g. coke, graphitic solids, or micro-agglomerated asphaltenes), iron rust and other oxidative corrosion solids, fine bulk metal particles, paint or surface coating particles, plastic or polymeric or elastomer or rubber particles (e.g. resulting from the degradation of gaskets, valve parts, etc. . . . ), catalyst fines, ceramic or mineral particles, sand, clay, and other earthen particles, bacteria and other biologically generated solids, and mixtures of these that may be present as suspended particles, but otherwise don't detract from the merchantable quality of the Heavy Marine Fuel Composition as an ISO 8217 (2017) compliant heavy (residual) marine fuel.

The blend of Product HMFO and Diluent Materials must be of merchantable quality as a low sulfur heavy (residual) marine fuel. That is the blend must be suitable for the intended use as heavy marine bunker fuel and generally be fungible as a bunker fuel for ocean going ships. Preferably the Heavy Marine Fuel Composition must retain the bulk physical properties required of an ISO 8217 (2017) compliant residual marine fuel oil and a sulfur content lower than the global MARPOL standard of 0.5% wt. sulfur (ISO 14596 or ISO 8754) so that the material qualifies as MARPOL Annex VI Low Sulfur Heavy Marine Fuel Oil (LS-HMFO). The sulfur content of the Product HMFO can be lower than 0.5% wt. (i.e. below 0.1% wt sulfur (ISO 14596 or ISO 8754)) to qualify as a MARPOL Annex VI compliant Ultra-Low Sulfur Heavy Marine Fuel Oil (ULS-HMFO) and a Heavy Marine Fuel Composition likewise can be formulated to qualify as a MARPOL Annex VI compliant ULS-HMFO suitable for use as marine bunker fuel in the ECA zones. The Heavy Marine Fuel Composition of the present invention must meet those internationally accepted standards for the bulk properties of residual marine fuel oils including: a kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s; a density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³; a CCAI is in the range of 780 to 870; a flash point (ISO 2719) no lower than 60° C.; a total sediment-aged (ISO 10307-2) less than 0.10 mass %; and a carbon residue-micro method (ISO 10370) less than 20.00 mass % and also preferably a maximum aluminum plus silicon (ISO 10478) content less than 60 mg/kg.

Production Plant Description: Turning now to a more detailed illustrative embodiment of a production plant implementing both the core process and the ultrasonic desulfurization processes disclosed, FIGS. 4 and 5 show a schematic for a production plant implementing the core process described above combined with a pre-treatment ultrasound treatment unit (UTU) (FIG. 4, item 2) or a post-treatment UTU (FIG. 5, item 18), the combination which will reduce the environmental contaminates in a Feedstock HMFO to produce a Product HMFO that is ISO 8217:2017 compliant and with the desired properties of a merchantable HMFO.

It will be appreciated by one of skill in the art that additional alternative embodiments for the core process and the UTU may involve multiple vessels and reactors even though only one of each is shown. Variations using multiple vessels/reactors are contemplated by the present invention but are not illustrated in greater detail for simplicity sake.

The Reactor System (11) for the core process is described in greater detail below and using multiple vessels process has been described. It will be noted by one of skill in the art that in FIGS. 4 and 5, portions of the production plant with similar function and operation have been assigned the same reference number. This has been done for convenience and succinctness only and differences between FIG. 4 and FIG. 5 are duly noted and explained below.

In FIGS. 4 and 5, Feedstock HMFO (A) is fed from outside the battery limits (OSBL) to the Oil Feed Surge Drum (1) that receives feed from outside the battery limits (OSBL) and provides surge volume adequate to ensure smooth operation of the unit. Water entrained in the feed is removed from the HMFO with the water being discharged a stream (1 c) for treatment OSBL.

As shown in FIG. 4, the Feedstock HMFO (A) is withdrawn from the Oil Feed Surge Drum (1) via line (1 b) by the Oil Feed Pump (3) and sent to the UTU 2 as a pretreatment step. The pre-treated Feedstock HMFO is pressurized to a pressure required for the process. The pressurized HMFO (A′) then passes through line (3 a) to the Oil Feed/Product Heat Exchanger (5) where the pressurized HMFO (A′) is partially heated by the Product HMFO (B). The pressurized Feedstock HMFO (A′) passing through line (5 a) is further heated against the effluent from the Reactor System (E) in the Reactor Feed/Effluent Heat Exchanger (7).

As shown in FIG. 5, the Feedstock HMFO (A) is withdrawn from the Oil Feed Surge Drum (1) via line (1 b) by the Oil Feed Pump (3) and is pressurized to a pressure required for the core process. The pressurized HMFO (A′) then passes through line (3 a) to the Oil Feed/Product Heat Exchanger (5) where the pressurized HMFO (A′) is partially heated by the Product HMFO (B). The pressurized Feedstock HMFO (A′) passing through line (5 a) is further heated against the effluent from the Reactor System (E) in the Reactor Feed/Effluent Heat Exchanger (7).

In both FIG. 4 and FIG. 5, the heated and pressurized Feedstock HMFO (A″) in line (7 a) is then mixed with Activating Gas (C) provided via line (23 c) at Mixing Point (X) to form a Feedstock Mixture (D). The mixing point (X) can be any well know gas/liquid mixing system or entrainment mechanism well known to one skilled in the art.

The Feedstock Mixture (D) passes through line (9 a) to the Reactor Feed Furnace (9) where the Feedstock Mixture (D) is heated to the specified process temperature. The Reactor Feed Furnace (9) may be a fired heater furnace or any other kind to type of heater as known to one of skill in the art if it will raise the temperature of the Feedstock mixture to the desired temperature for the process conditions.

The heated Feedstock Mixture (D′) exits the Reactor Feed Furnace (9) via line 9 b and is fed into the Reactor System (11). The heated Feedstock Mixture (D′) enters the Reactor System (11) where environmental contaminates, such a sulfur, nitrogen, and metals are preferentially removed from the Feedstock HMFO component of the heated Feedstock Mixture. The Reactor System contains a catalyst which preferentially removes the sulfur compounds in the Feedstock HMFO component by reacting them with hydrogen in the Activating Gas to form hydrogen sulfide. The Reactor System will also achieve demetalization, denitrogenation, and a certain amount of ring opening hydrogenation of the complex aromatics and asphaltenes, however minimal hydrocracking of hydrocarbons should take place. The process conditions of hydrogen partial pressure, reaction pressure, temperature and residence time as measured by liquid hourly velocity are optimized to achieve desired final product quality. A more detailed discussion of the Reactor System, the catalyst, the process conditions, and other aspects of the process are contained below in the “Reactor System Description.”

The Reactor System Effluent (E) exits the Reactor System (11) via line (11 a) and exchanges heat against the pressurized and partially heats the Feedstock HMFO (A′) in the Reactor Feed/Effluent Exchanger (7). The partially cooled Reactor System Effluent (E′) then flows via line (11 c) to the Hot Separator (13).

The Hot Separator (13) separates the gaseous components of the Reactor System Effluent (F) which are directed to line (13 a) from the liquid components of the Reactor System effluent (G) which are directed to line (13 b). The gaseous components of the Reactor System effluent in line (13 a) are cooled against air in the Hot Separator Vapor Air Cooler (15) and then flow via line (15 a) to the Cold Separator (17).

The Cold Separator (17) further separates any remaining gaseous components from the liquid components in the cooled gaseous components of the Reactor System Effluent (F′). The gaseous components from the Cold Separator (F″) are directed to line (17 a) and fed onto the Amine Absorber (21). The Cold Separator (17) also separates any remaining Cold Separator hydrocarbon liquids (H) in line (17 b) from any Cold Separator condensed liquid water (I). The Cold Separator condensed liquid water (I) is sent OSBL via line (17 c) for treatment.

In FIG. 4, the hydrocarbon liquid components of the Reactor System effluent from the Hot Separator (G) in line (13 b) and the Cold Separator hydrocarbon liquids (H) in line (17 b) are combined and are fed to the Oil Product Stripper System (19). The Oil Product Stripper System (19) removes any residual hydrogen and hydrogen sulfide from the Product HMFO (B) which is discharged in line (19 b) to storage OSBL. It is also contemplated that a second draw (not shown) may be included to withdraw a distillate product, preferably a middle to heavy distillate. The vent stream (M) from the Oil Product Stripper in line (19 a) may be sent to the fuel gas system or to the flare system that are OSBL.

In FIG. 5, the hydrocarbon liquid components of the Reactor System effluent from the Hot Separator (G) in line (13 b) and the Cold Separator hydrocarbon liquids (H) in line (17 b) are combined and are fed to the UTU (18) prior to being sent to the Oil Product Stripper System (19). The Oil Product Stripper System (19) removes any residual hydrogen and hydrogen sulfide from the Product HMFO (B) which is discharged in line (19 b) to storage OSBL. The vent stream (M) from the Oil Product Stripper in line (19 a) may be sent to the fuel gas system or to the flare system that are OSBL.

An alternative embodiment not shown in FIG. 5, but well within the skill of one in the art, would be to relocate the UTU (18) from the line prior to the Oil Product Stripper (19) to a location downstream of the Oil Product Stripper (19). Such a relocation of the UTU (18) to line (19 b) will allow for the ultrasound treatment of the final product HMFO prior to being sent to storage OSBL. This location is practicable because the UTU may induce desirable changes in the product HMFO without substantial production of light hydrocarbons (i.e. minimal cracking). The UTU may also impart an additional amount of stability to the Product HMFO.

The gaseous components from the Cold Separator (F″) in line (17 a) contain a mixture of hydrogen, hydrogen sulfide and light hydrocarbons (mostly methane and ethane). This vapor stream (17 a) feeds an Amine Absorber (21) where it is contacted against Lean Amine (J) provided OSBL via line (21 a) to the Amine Absorber (21) to remove hydrogen sulfide from the gases making up the Activating Gas recycle stream (C′). Rich amine (K) which has absorbed hydrogen sulfide exits the bottom of the Amine Absorber (21) and is sent OSBL via line (21 b) for amine regeneration and sulfur recovery.

The Amine Absorber overhead vapor in line (21 c) is preferably recycled to the process as a Recycle Activating Gas (C′) via the Recycle Compressor (23) and line (23 a) where it is mixed with the Makeup Activating Gas (C″) provided OSBL by line (23 b). This mixture of Recycle Activating Gas (C′) and Makeup Activating Gas (C″) to form the Activating Gas (C) utilized in the process via line (23 c) as noted above. A Scrubbed Purge Gas stream (H) is taken from the Amine Absorber overhead vapor line (21 c) and sent via line (21 d) to OSBL to prevent the buildup of light hydrocarbons or other non-condensables.

Reactor System Description: The core process Reactor System (11) illustrated in FIG. 4 and FIG. 5 comprises a single reactor vessel loaded with the process catalyst and sufficient controls, valves and sensors as one of skill in the art would readily appreciate.

Alternative Reactor Systems in which more than one reactor vessel may be utilized in parallel or in a cascading series can easily be substituted for the single reactor vessel Reactor System 11 shown. In such an embodiment, each reactor vessel is similarly loaded with process catalyst and can be provided the heated Feed Mixture (D′) via a common line. The effluent from each of the three reactors is recombined in line and forms a combined Reactor Effluent (E) for further processing as described above. The illustrated arrangement will allow the three reactors to carry out the process effectively multiplying the hydraulic capacity of the overall Reactor System. Control valves and isolation valves may also prevent feed from entering one reactor vessel but not another reactor vessel. In this way one reactor can be by-passed and placed off-line for maintenance and reloading of catalyst while the remaining reactors continues to receive heated Feedstock Mixture (D′). It will be appreciated by one of skill in the art this arrangement of reactor vessels in parallel is not limited in number to three, but multiple additional reactor vessels can be added. The only limitation to the number of parallel reactor vessels is plot spacing and the ability to provide heated Feedstock Mixture (D′) to each active reactor.

In another illustrative embodiment cascading reactor vessels are loaded with process catalyst with the same or different activities toward metals, sulfur or other environmental contaminates to be removed. For example, one reactor may be loaded with a highly active demetallization catalyst, a second subsequent or downstream reactor may be loaded with a balanced demetallization/desulfurizing catalyst, and reactor downstream from the second reactor may be loaded with a highly active desulfurization catalyst. This allows for greater control and balance in process conditions (temperature, pressure, space flow velocity, etc. . . . ) so it is tailored for each catalyst. In this way one can optimize the parameters in each reactor depending upon the material being fed to that specific reactor/catalyst combination and minimize the hydrocracking reactions. As with the prior illustrative embodiment, multiple cascading series of reactors can be utilized in parallel and in this way the benefits of such an arrangement noted above (i.e. allow one series to be “online” while the other series is “off line” for maintenance or allow increased plant capacity).

The reactor(s) that form the Reactor System may be fixed bed, ebulliated bed or slurry bed or a combination. As envisioned, fixed bed reactors are preferred as these are easier to operate and maintain.

The reactor vessel in the Reactor System is loaded with one or more process catalysts. The exact design of the process catalyst system is a function of feedstock properties, product requirements and operating constraints and optimization of the process catalyst can be carried out by routine trial and error by one of ordinary skill in the art.

The process catalyst(s) comprise at least one metal selected from the group consisting of the metals each belonging to the groups 6, 8, 9 and 10 of the Periodic Table, and more preferably a mixed transition metal catalyst such as Ni—Mo, Co—Mo, Ni—W or Ni—Co—Mo are utilized. The metal is preferably supported on a porous inorganic oxide catalyst carrier. The porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier. The preferred porous inorganic oxide catalyst carrier is alumina. The pore size and metal loadings on the carrier may be systematically varied and tested with the desired feedstock and process conditions to optimize the properties of the Product HMFO. Such activities are well known and routine to one of skill in the art. Catalyst in the fixed bed reactor(s) may be dense-loaded or sock-loaded.

The catalyst selection utilized within and for loading the Reactor System may be preferential to desulfurization by designing a catalyst loading scheme that results in the Feedstock mixture first contacting a catalyst bed that with a catalyst preferential to demetallization followed downstream by a bed of catalyst with mixed activity for demetallization and desulfurization followed downstream by a catalyst bed with high desulfurization activity. In effect the first bed with high demetallization activity acts as a guard bed for the desulfurization bed.

The objective of the Reactor System is to treat the Feedstock HMFO at the severity required to meet the Product HMFO specification. Demetallization, denitrogenation and hydrocarbon hydrogenation reactions may also occur to some extent when the process conditions are optimized so performing the Reactor System achieves the required level of desulfurization. Hydrocracking is preferably minimized to reduce the volume of hydrocarbons formed as by-product hydrocarbons to the process. The objective of the process is to selectively remove the environmental contaminates from Feedstock HMFO and minimize the formation of unnecessary by-product hydrocarbons.

The process reactive conditions in each reactor vessel will depend upon the feedstock, the catalyst utilized and the desired final properties of the Product HMFO desired. Variations in conditions are to be expected by one of ordinary skill in the art and these may be determined by pilot plant testing and systematic optimization of the process. With this in mind it has been found that the operating pressure, the indicated operating temperature, the ratio of the Activating Gas to Feedstock HMFO, the partial pressure of hydrogen in the Activating Gas and the space velocity all are important parameters to consider. The operating pressure of the Reactor System should be in the range of 250 psig and 3000 psig, preferably between 1000 psig and 2500 psig and more preferably between 1500 psig and 2200 psig. The indicated operating temperature of the Reactor System should be 500° F. to 900° F., preferably between 650° F. and 850° F. and more preferably between 680° F. and 800° F. The ratio of the quantity of the Activating Gas to the quantity of Feedstock HMFO should be in the range of 250 scf gas/bbl of Feedstock HMFO to 10,000 scf gas/bbl of Feedstock HMFO, preferably between 2000 scf gas/bbl of Feedstock HMFO to 5000 scf gas/bbl of Feedstock HMFO and more preferably between 2500 scf gas/bbl of Feedstock HMFO to 4500 scf gas/bbl of Feedstock HMFO. The Activating Gas should be selected from mixtures of nitrogen, hydrogen, carbon dioxide, gaseous water, and methane, so Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of the total pressure of the Activating Gas mixture (P) and preferably wherein the Activating Gas has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 95% of the total pressure of the Activating Gas mixture (P). The Activating Gas may have a hydrogen mole fraction in the range between 80% of the total moles of Activating Gas mixture and more preferably wherein the Activating Gas has a hydrogen mole fraction between 80% and 99% of the total moles of Activating Gas mixture. The liquid hourly space velocity within the Reactor System should be between 0.05 oil/hour/m3 catalyst and 1.0 oil/hour/m3 catalyst; preferably between 0.08 oil/hour/m3 catalyst and 0.5 oil/hour/m3 catalyst and more preferably between 0.1 oil/hour/m3 catalyst and 0.3 oil/hour/m3 catalyst to achieve deep desulfurization with product sulfur levels below 0.1 ppmw.

The hydraulic capacity rate of the Reactor System should be between 100 bbl of Feedstock HMFO/day and 100,000 bbl of Feedstock HMFO/day, preferably between 1000 bbl of Feedstock HMFO/day and 60,000 bbl of Feedstock HMFO/day, more preferably between 5,000 bbl of Feedstock HMFO/day and 45,000 bbl of Feedstock HMFO/day, and even more preferably between 10,000 bbl of Feedstock HMFO/day and 30,000 bbl of Feedstock HMFO/day. The desired hydraulic capacity may be achieved in a single reactor vessel Reactor System or in a multiple reactor vessel Reactor System.

These examples will provide one skilled in the art with a more specific illustrative embodiment for conducting the process disclosed and claimed herein:

Example 1 Overview:

The purpose of a pilot test run is to demonstrate that feedstock HMFO can be processed through a reactor loaded with commercially available catalysts at specified conditions to remove environmental contaminates, specifically sulfur and other contaminants from the HMFO to produce a product HMFO that is MARPOL compliant, that is production of a Low Sulfur Heavy Marine Fuel Oil (LS-HMFO) or Ultra-Low Sulfur Heavy Marine Fuel Oil (USL-HMFO).

Pilot Unit Set Up:

The pilot unit will be set up with two 434 cm³ reactors arranged in series to process the feedstock HMFO. The lead reactor will be loaded with a blend of a commercially available hydro-demetaling (HDM) catalyst and a commercially available hydro-transition (HDT) catalyst. One of skill in the art will appreciate that the HDT catalyst layer may be formed and optimized using a mixture of HDM and HDS catalysts combined with an inert material to achieve the desired intermediate/transition activity levels. The second reactor will be loaded with a blend of the commercially available hydro-transition (HDT) and a commercially available hydrodesulfurization (HDS). One can load the second reactor simply with a commercially hydrodesulfurization (HDS) catalyst. One of skill in the art will appreciate that the specific feed properties of the Feedstock HMFO may affect the proportion of HDM, HDT and HDS catalysts in the reactor system. A systematic process of testing different combinations with the same feed will yield the optimized catalyst combination for any feedstock and reaction conditions. For this example, the first reactor will be loaded with ⅔ hydro-demetaling catalyst and ⅓ hydro-transition catalyst. The second reactor will be loaded with all hydrodesulfurization catalyst. The catalysts in each reactor will be mixed with glass beads (approximately 50% by volume) to improve liquid distribution and better control reactor temperature. For this pilot test run, one should use these commercially available catalysts: HDM: Albemarle KFR 20 series or equivalent; HDT: Albemarle KFR 30 series or equivalent; HDS: Albemarle KFR 50 or KFR 70 or equivalent. Once set up of the pilot unit is complete, the catalyst can be activated by sulfiding the catalyst using dimethyldisulfide (DMDS) in a manner well known to one of skill in the art.

Pilot Unit Operation:

Upon completion of the activating step, the pilot unit will be ready to receive the feedstock HMFO and Activating Gas feed. For the present example, the Activating Gas can be technical grade or better hydrogen gas. The mixed Feedstock HMFO and Activating Gas will be provided to the pilot plant at rates and operating conditions as specified: Oil Feed Rate: 108.5 ml/h (space velocity=0.25/h); Hydrogen/Oil Ratio: 570 Nm3/m3 (3200 scf/bbl); Reactor Temperature: 372° C. (702° F.); Reactor Outlet Pressure: 13.8 MPa(g) (2000 psig).

One of skill in the art will know that the rates and conditions may be systematically adjusted and optimized depending upon feed properties to achieve the desired product requirements. The unit will be brought to a steady state for each condition and full samples taken so analytical tests can be completed. Material balance for each condition should be closed before moving to the next condition.

Expected impacts on the Feedstock HMFO properties are: Sulfur Content (wt %): Reduced by at least 80%; Metals Content (wt %): Reduced by at least 80%; MCR/Asphaltene Content (wt %): Reduced by at least 30%; Nitrogen Content (wt %): Reduced by at least 20%; C1-Naphtha Yield (wt %): Not over 3.0% and preferably not over 1.0%.

Process conditions in the Pilot Unit can be systematically adjusted as per Table 1 to assess the impact of process conditions and optimize the performance of the process for the specific catalyst and feedstock HMFO utilized.

TABLE 1 Optimization of Process Conditions HC Feed Rate (ml/h), Nm³ H₂/m³ oil/ Temp Pressure Case [LHSV(/h)] scf H₂/bbl oil (° C./° F.) (MPa(g)/psig) Baseline 108.5 [0.25] 570/3200 372/702 13.8/2000 T1 108.5 [0.25] 570/3200 362/684 13.8/2000 T2 108.5 [0.25] 570/3200 382/720 13.8/2000 L1 130.2 [0.30] 570/3200 372/702 13.8/2000 L2  86.8 [0.20] 570/3200 372/702 13.8/2000 H1 108.5 [0.25] 500/2810 372/702 13.8/2000 H2 108.5 [0.25] 640/3590 372/702 13.8/2000 S1  65.1 [0.15] 620/3480 385/725 15.2/2200

In this way, the conditions of the pilot unit can be optimized to achieve less than 0.5% wt. sulfur product HMFO and preferably a 0.1% wt. sulfur product HMFO. Conditions for producing ULS-HMFO (i.e. 0.1% wt. sulfur product HMFO) will be: Feedstock HMFO Feed Rate: 65.1 ml/h (space velocity=0.15/h); Hydrogen/Oil Ratio: 620 Nm³/m³ (3480 scf/bbl); Reactor Temperature: 385° C. (725° F.); Reactor Outlet Pressure: 15 MPa(g) (2200 psig)

Table 2 summarizes the anticipated impacts on key properties of HMFO.

TABLE 2 Expected Impact of Process on Key Properties of HMFO Property Minimum Typical Maximum Sulfur Conversion/Removal 80% 90% 98% Metals Conversion/Removal 80% 90% 100%  MCR Reduction 30% 50% 70% Asphaltene Reduction 30% 50% 70% Nitrogen Conversion 10% 30% 70% C1 through Naphtha Yield 0.5%  1.0%  4.0%  Hydrogen Consumption (scf/bbl) 500 750 1500

Table 3 lists analytical tests to be carried out for the characterization of the Feedstock HMFO and Product HMFO. The analytical tests include those required by ISO for the Feedstock HMFO and the product HMFO to qualify and trade in commerce as ISO compliant residual marine fuels. The additional parameters are provided so that one skilled in the art can understand and appreciate the effectiveness of the inventive process.

TABLE 3 Analytical Tests and Testing Procedures Sulfur Content ISO 8754 or ISO 14596 or ASTM D4294 Density @ 15° C. ISO 3675 or ISO 12185 Kinematic Viscosity @ 50° C. ISO 3104 Pour Point, ° C. ISO 3016 Flash Point, ° C. ISO 2719 CCAI ISO 8217, ANNEX B Ash Content ISO 6245 Total Sediment - Aged ISO 10307-2 Micro Carbon Residue, mass % ISO 10370 H2S, mg/kg IP 570 Acid Number ASTM D664 Water ISO 3733 Specific Contaminants IP 501 or IP 470 (unless indicated otherwise) Vanadium or ISO 14597 Sodium Aluminum or ISO 10478 Silicon or ISO 10478 Calcium or IP 500 Zinc or IP 500 Phosphorous IP 500 Nickle Iron Distillation ASTM D7169 C:H Ratio ASTM D3178 SARA Analysis ASTM D2007 Asphaltenes, wt % ASTM D6560 Total Nitrogen ASTM D5762 Vent Gas Component Analysis FID Gas Chromatography or comparable

Table 4 contains the Feedstock HMFO analytical test results and the Product HMFO analytical test results expected from the inventive process that indicate the production of a LS HMFO. It will be noted by one of skill in the art that under the conditions, the levels of hydrocarbon cracking will be minimized to levels substantially lower than 10%, more preferably less than 5% and even more preferably less than 1% of the total mass balance.

TABLE 4 Analytical Results Feedstock HMFO Product HMFO Sulfur Content, mass % 3.0   0.3 Density @ 15° C., kg/m³ 990 950 ⁽¹⁾ Kinematic Viscosity @ 380 100 ⁽¹⁾ 50° C., mm²/s Pour Point, ° C. 20 10  Flash Point, ° C. 110 100 ⁽¹⁾ CCAI 850 820  Ash Content, mass % 0.1   0.0 Total Sediment - Aged, mass % 0.1   0.0 Micro Carbon Residue, mass % 13.0   6.5 H2S, mg/kg 0 0 Acid Number, mg KO/g 1   0.5 Water, vol % 0.5 0 Specific Contaminants, mg/kg Vanadium 180 20  Sodium 30 1 Aluminum 10 1 Silicon 30 3 Calcium 15 1 Zinc 7 1 Phosphorous 2 0 Nickle 40 5 Iron 20 2 Distillation, ° C./° F. IBP 160/320 120/248  5% wt 235/455 225/437 10% wt 290/554 270/518 30% wt 410/770 370/698 50% wt  540/1004 470/878 70% wt  650/1202  580/1076 90% wt  735/1355  660/1220 FBP  820/1508  730/1346 C:H Ratio (ASTM D3178) 1.2   1.3 SARA Analysis Saturates 16 22  Aromatics 50 50  Resins 28 25  Asphaltenes 6 3 Asphaltenes, wt % 6.0   2.5 Total Nitrogen, mg/kg 4000 3000   Note: ⁽¹⁾ property will be adjusted to a higher value by post process removal of light material via distillation or stripping from product HMFO.

The product HMFO produced by the inventive process will reach ULS HMFO limits (i.e. 0.1% wt. sulfur product HMFO) by systematic variation of the process parameters, for example by a lower space velocity or by using a Feedstock HMFO with a lower initial sulfur content.

Example 2: RMG-380 HMFO Pilot Unit Set Up:

A pilot unit was set up as noted above in Example 1 with these changes: the first reactor was loaded with: as the first (upper) layer encountered by the feedstock 70% vol Albemarle KFR 20 series hydro-demetaling catalyst and 30% vol Albemarle KFR 30 series hydro-transition catalyst as the second (lower) layer. The second reactor was loaded with 20% Albemarle KFR 30 series hydrotransition catalyst as the first (upper) layer and 80% vol hydrodesulfurization catalyst as the second (lower) layer. The catalyst was activated by sulfiding the catalyst with dimethyldisulfide (DMDS) in a manner well known to one of skill in the art.

Pilot Unit Operation:

Upon completion of the activating step, the pilot unit was ready to receive the feedstock HMFO and Activating Gas feed. The Activating Gas was technical grade or better hydrogen gas. The Feedstock HMFO was a commercially available and merchantable ISO 8217 (2017) compliant HMFO, except for a high sulfur content (2.9 wt %). The mixed Feedstock HMFO and Activating Gas was provided to the pilot plant at rates and conditions as specified in Table 5 below. The conditions were varied to optimize the level of sulfur in the product HMFO material.

TABLE 5 Process Conditions Product HC Feed Nm³ H₂/ Temp Pressure HMFO Rate (ml/h), m³ oil/scf (° C./ (MPa(g)/ Sulfur Case [LHSV(/h)] H₂/bbl oil ° F.) psig) % wt. Baseline 108.5 [0.25] 570/3200 371/700 13.8/2000 0.24 T1 108.5 [0.25] 570/3200 362/684 13.8/2000 0.53 T2 108.5 [0.25] 570/3200 382/720 13.8/2000 0.15 L1 130.2 [0.30] 570/3200 372/702 13.8/2000 0.53 S1  65.1 [0.15] 620/3480 385/725 15.2/2200 0.10 P1 108.5 [0.25] 570/3200 371/700    /1700 0.56 T2/P1 108.5 [0.25] 570/3200 382/720    /1700 0.46

Analytical data for a representative sample of the feedstock HMFO and representative samples of product HMFO are below:

TABLE 6 Analytical Results - HMFO (RMG-380) Feedstock Product Product Sulfur Content, mass % 2.9 0.3 0.1 Density @ 15° C., kg/m³ 988 932 927 Kinematic Viscosity @ 382 74 47 50° C., mm²/s Pour Point, ° C. −3 −12 −30 Flash Point, ° C. 116 96 90 CCAI 850 812 814 Ash Content, mass % 0.05 0.0 0.0 Total Sediment - Aged, 0.04 0.0 0.0 mass % Micro Carbon Residue, 11.5 3.3 4.1 mass % H2S, mg/kg 0.6 0 0 Acid Number, mg KO/g 0.3 0.1 >0.05 Water, vol % 0 0.0 0.0 Specific Contaminants, mg/kg Vanadium 138 15 <1 Sodium 25 5 2 Aluminum 21 2 <1 Silicon 16 3 1 Calcium 6 2 <1 Zinc 5 <1 <1 Phosphorous <1 2 1 Nickle 33 23 2 Iron 24 8 1 Distillation, ° C./° F. IBP 178/352 168/334 161/322  5% wt 258/496 235/455 230/446 10% wt 298/569 270/518 264/507 30% wt 395/743 360/680 351/664 50% wt 517/962 461/862 439/822 70% wt  633/1172  572/1062  552/1026 90% wt  >720/>1328  694/1281  679/1254 FBP  >720/>1328  >720/>1328  >720/>1328 C:H Ratio (ASTM D3178) 1.2 1.3 1.3 SARA Analysis Saturates 25.2 28.4 29.4 Aromatics 50.2 61.0 62.7 Resins 18.6 6.0 5.8 Asphaltenes 6.0 4.6 2.1 Asphaltenes, wt % 6.0 4.6 2.1 Total Nitrogen, mg/kg 3300 1700 1600

In Table 6, both feedstock HMFO and product HMFO exhibited observed bulk properties consistent with ISO 8217 (2017) for a merchantable residual marine fuel oil, except that the sulfur content of the product HMFO was reduced as noted above when compared to the feedstock HMFO.

One of skill in the art will appreciate that the above product HMFO produced by the inventive process has achieved not only an ISO 8217 (2017) compliant LS HMFO (i.e. 0.5% wt. sulfur) but also an ISO 8217 (2017) compliant ULS HMFO limits (i.e. 0.1% wt. sulfur) product HMFO.

Example 3: RMK-500 HMFO

The feedstock to the pilot reactor utilized in example 2 above was changed to a commercially available and merchantable ISO 8217 (2017) RMK-500 compliant HMFO, except that it has high environmental contaminates (i.e. sulfur (3.3 wt %)). Other bulk characteristic of the RMK-500 feedstock high sulfur HMFO are provide below:

TABLE 7 Analytical Results- Feedstock HMFO (RMK-500) Sulfur Content, mass % 3.3 Density @ 15° C., kg/m³ 1006 Kinematic Viscosity @ 50° C., mm²/s 500

The mixed Feedstock (RMK-500) HMFO and Activating Gas was provided to the pilot plant at rates and conditions and the resulting sulfur levels achieved in the table below

TABLE 8 Process Conditions HC Feed Rate Product (ml/h), Nm³ H₂/m³ oil/ Temp Pressure (RMK-500) Case [LHSV(/h)] scf H₂/bbl oil (° C./° F.) (MPa(g)/psig) sulfur % wt. A 108.5 [0.25]  640/3600 377/710 13.8/2000 0.57 B 95.5 [0.22] 640/3600 390/735 13.8/2000 0.41 C 95.5 [0.22] 640/3600 390/735 11.7/1700 0.44 D 95.5 [0.22] 640/3600 393/740 10.3/1500 0.61 E 95.5 [0.22] 640/3600 393/740 17.2/2500 0.37 F 95.5 [0.22] 640/3600 393/740  8.3/1200 0.70 G 95.5 [0.22] 640/3600 416/780  8.3/1200

The resulting product (RMK-500) HMFO exhibited observed bulk properties consistent with the feedstock (RMK-500) HMFO, except that the sulfur content was reduced as noted in the above table.

One of skill in the art will appreciate that the above product HMFO produced by the inventive process has achieved a LS HMFO (i.e. 0.5% wt. sulfur) product HMFO having bulk characteristics of a ISO 8217 (2017) compliant RMK-500 residual fuel oil. It will also be appreciated that the process can be successfully carried out under non-hydrocracking conditions (i.e. lower temperature and pressure) that substantially reduce the hydrocracking of the feedstock material. When conditions were increased to much higher pressure (Example E) a product with a lower sulfur content was achieved, however some observed that there was an increase in light hydrocarbons and wild naphtha production.

This prophetic example will provide one skilled in the art with a more specific illustrative embodiment for conducting the processes disclosed:

Prophetic Example of Ultrasound Treatment Unit Operation:

To exemplify the invention, experiments will be carried out using reaction system disclosed in U.S. Pat. No. 4,168,295 or 6,897,628 and the high powered ultrasonic transducers disclosed in U.S. Pat. No. 7,275,440. A simple tube based flow through reactor such as those disclosed in US20090038932 or U.S. Pat. No. 9,339,785 if a catalyst material is to be present. In the present example a simple tube reactor with a supported catalyst material such as that described in U.S. Pat. No. 9,339,785 is preferable. Associated pumps, heater, hydrogen gas mixers and feedstock HMFO material (either Feedstock HMFO or Product HMFO from the prior process) will be connected to the tube reactor in a conventional manner. The feedstock should be heated so is has sufficient fluidity for pumping and flow through the reactor, preferably this will be between about 150° C. and about 300° C. The ultrasound transducer operating conditions used to process the ultrasound will be well known to one of skill in the art. The acoustic power will be systematically varied between about 200 W and 1000 W, however this will be dynamically optimized depending upon the Feedstock and the desired degree of desulfurization desired. The reactor temperature must be carefully monitored and the feedstock flow increased or decreased to control the reaction temperature in the range of about 200° C. and 400° C. The final nominal temperature of the product between 230° C. and 300° C. The reactionary system may have mechanical stirring within the reaction bed itself in the form of static mixing elements or other inert packing materials. The catalysts chosen for this study were, NiMo or CoMo type, with metal sulfides as an active phase. With these catalysts the aim was to conjugate in a synergic and localized form in the same active sites, the remaining catalytic activity during the active phase with its high capacity to absorb ultrasounds. Hydrogen will be preferably present during the ultrasound treatment the reaction zone at a pressure ranging from one atmosphere to 400 psig.

It is expected that besides the desulfurization of the feedstock HMFO, the viscosity of the HMFO will be modified in such a manner to make it less viscous. In this way a highly viscous residual based high sulfur Feedstock HMFO otherwise ISO 8217 compliant, such as RMG 500 (Kinematic Viscosity of 500 at 50° C.) or RMG700 (Kinematic Viscosity of 500) at 50° C. or even RMK500 or 700, may be more easily introduced in the core process and processed with less formation of coke and other particles that may cause a rapid increase in reactor backpressure. As part of the post Core Process treatment of the Product HMFO, the described process will be carried out to condition the Product HMFO for easier transport and handling, increased compatibility and stability when blended with other marine fuel materials (i.e. MGO or MDO), and enhance the value of these materials as low sulfur HMFO.

Table 9 contains the expected analytical test results for (A) Feedstock HMFO; (B) the Core Process Product HMFO and (C) Overall Process (Core+post ultrasound treatment) from the inventive processes. These results will indicate to one of skill in the art that the production of a ULS HMFO can be achieved and will demonstrate the benefits of ultrasonic treatment of HMFO. It will be noted by one of skill in the art that under the conditions, the levels of hydrocarbon cracking will be minimized to levels substantially lower than 10%, more preferably less than 5% and even more preferably less than 1% of the total mass balance.

TABLE 9 Analytical Results A B C Sulfur Content, mass % 3.0 Less than 0.5 Less than 0.1 Density @ 15° C., kg/m³ 990 950 ⁽¹⁾ 950 ⁽¹⁾ Kinematic Viscosity @ 380 100 ⁽¹⁾ <100 ⁽¹⁾  50° C., mm²/s Pour Point, ° C. 20 10  10  Flash Point, ° C. 110 100 ⁽¹⁾ 100 ⁽¹⁾ CCAI 850 820  820  Ash Content, mass % 0.1   0.0   0.0 Total Sediment - Aged, 0.1   0.0   0.0 mass % Micro Carbon Residue, 13.0   6.5   6.5 mass % H2S, mg/kg 0 0 0 Acid Number, mg KO/g 1   0.5 Less than 0.5 Water, vol % 0.5 0 0 Specific Contaminants, mg/kg Vanadium 180 20  20  Sodium 30 1 1 Aluminum 10 1 1 Silicon 30 3 3 Calcium 15 1 1 Zinc 7 1 1 Phosphorous 2 0 0 Nickle 40 5 5 Iron 20 2 2 Distillation, ° C./° F. IBP 160/320 120/248 120/248  5% wt 235/455 225/437 225/437 10% wt 290/554 270/518 270/518 30% wt 410/770 370/698 370/698 50% wt  540/1004 470/878 470/878 70% wt  650/1202  580/1076  580/1076 90% wt  735/1355  660/1220  660/1220 FBP  820/1508  730/1346  730/1346 C:H Ratio (ASTM D3178) 1.2   1.3   1.3 SARA Analysis Saturates 16 22  22  Aromatics 50 50  50  Resins 28 25  25  Asphaltenes 6 3 3 Asphaltenes, wt % 6.0   2.5   2.5 Total Nitrogen, mg/kg 4000 3000   3000   Note: ⁽¹⁾ property may be adjusted to a higher value by post process removal of light material via distillation or stripping.

It will be appreciated by those skilled in the art that changes could be made to the illustrative embodiments described above without departing from the broad inventive concepts thereof. It is understood, therefore, that the inventive concepts disclosed are not limited to the illustrative embodiments or examples disclosed, but it is intended to cover modifications within the scope of the inventive concepts as defined by the claims. 

1. A process for reducing the environmental contaminants in a Feedstock Heavy Marine Fuel Oil, the process comprising: contacting a Feedstock Heavy Marine Fuel Oil, wherein the Feedstock Heavy Marine Fuel Oil complies with ISO 8217 except for the environmental contaminates including a sulfur content (ISO 14596 or ISO 8754) greater than 0.50 wt %, with ultrasound having a frequency in the range of about 10 kHz and about 100 megahertz and a sonic energy in the range of about 30 watts/cm² to about 300 watts/cm², and a temperature ranging between 30° C. and 260° C. to give an ultrasonic pre-treated Feedstock Heavy Marine Fuel Oil; mixing a quantity of the ultrasonic pre-treated Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more supported transition metal catalysts under reactive conditions to form a Process Mixture from said Feedstock Mixture; receiving said Process Mixture and separating the Product Heavy Marine Fuel Oil liquid components of the Process Mixture from the gaseous components and by-product hydrocarbon components of the Process Mixture and, discharging the Product Heavy Marine Fuel Oil.
 2. The process of claim 1, wherein the step of contacting a Feedstock Heavy Marine Fuel Oil with ultrasound takes place in the presence of water or supercritical water in which the volume ratio of the Feedstock Heavy Marine Fuel Oil to the water is from about 25:1 to about 1:5.
 3. The process of claim 2, wherein the step of contacting a Feedstock Heavy Marine Fuel Oil with ultrasound further takes place in the presence of an oxidizing agent selected from the group consisting of hydrogen peroxide or a water soluble organic peroxide.
 4. The process of claim 1, wherein the step of contacting a Feedstock Heavy Marine Fuel Oil with ultrasound takes place in the presence of one or more metal catalysts having atomic numbers of 21 through 29, 39 through 47, and 57 through
 79. 5. The process of claim 1, wherein the step of contacting a Feedstock Heavy Marine Fuel Oil with ultrasound takes place in the presence of one or more metal catalysts selected from the group consisting of: Fenton's reagent; tungstic acid, phosphotungstic acid, and metal ion catalyst salts in which the metal is iron (II), iron (III), copper (I), copper (II), chromium (III), chromium (VI), molybdenum, tungsten, and vanadium ions.
 6. The process of claim 1, wherein the step of contacting a Feedstock Heavy Marine Fuel Oil with ultrasound takes place at a space velocity in the range from 0.10 h⁻¹ and 10 h⁻¹.
 7. The process of claim 1, wherein the supported transition metal catalyst comprises: a porous inorganic oxide catalyst carrier and a transition metal catalyst, wherein the porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier, and wherein the transition metal catalyst is one or more metals selected from the group consisting of group 6, 8, 9 and 10 of the Periodic Table and wherein the Activating Gas mixture includes hydrogen gas and has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of the total pressure of the gas mixture (P).
 8. The process of claim 7, wherein the contacting the Feedstock Mixture with one or more supported transition metal catalysts under reactive conditions is selected from the group consisting of: a ratio of the quantity of the Activating Gas to the quantity of Feedstock Heavy Marine Fuel Oil in the range of 250 scf gas/bbl of Feedstock Heavy Marine Fuel Oil to 10,000 scf gas/bbl of Feedstock Heavy Marine Fuel Oil; a total pressure between of 250 psig and 3000 psig; an indicated temperature between of 500° F. to 900° F., and, wherein a liquid hourly space velocity is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³ catalyst.
 9. A process for reducing the environmental contaminants in a Feedstock Heavy Marine Fuel Oil, the process comprising: mixing a quantity of Feedstock Heavy Marine Fuel Oil, wherein the Feedstock Heavy Marine Fuel Oil complies with ISO 8217 except for the environmental contaminates including a sulfur content (ISO 14596 or ISO 8754) greater than 0.50 wt %, with a quantity of Activating Gas mixture to give a Feedstock Mixture; contacting the Feedstock Mixture with one or more catalysts under reactive conditions to form a Process Mixture from said Feedstock Mixture; receiving said Process Mixture and separating the hydrocarbon liquid components of the Process Mixture from the bulk gaseous components of the Process Mixture; receiving said hydrocarbon liquid components of the Process Mixture and contacting said hydrocarbon liquid components of the Process Mixture with ultrasound having a frequency in the range of about 10 kHz and about 100 megahertz and a sonic energy in the range of about 30 watts/cm² to about 300 watts/cm², and a temperature ranging between 30° C. and 260° C. to give an ultrasonic treated hydrocarbon liquid component of the Process Mixture; subsequently separating any residual gaseous components and by-product hydrocarbon components from the ultrasonic treated hydrocarbon liquid components of the Process Mixture to form the Product Heavy Marine Fuel Oil; and, discharging the Product Heavy Marine Fuel Oil.
 10. The process of claim 9, wherein the step of contacting said hydrocarbon liquid components of the Process Mixture with ultrasound takes place in the presence of water or supercritical water in which the volume ratio of the hydrocarbon liquid components to the water is from about 25:1 to about 1:5.
 11. The process of claim 10, wherein the step of contacting said hydrocarbon liquid components of the Process Mixture further takes place in the presence of an oxidizing agent selected from the group consisting of hydrogen peroxide or a water soluble organic peroxide.
 12. The process of claim 9, wherein the step of contacting said hydrocarbon liquid components of the Process Mixture with ultrasound takes place in the presence of one or more metal catalysts having atomic numbers of 21 through 29, 39 through 47, and 57 through
 79. 13. The process of claim 9, wherein the step of contacting said hydrocarbon liquid components of the Process Mixture with ultrasound takes place in the presence of one or more metal catalysts selected from the group consisting of: Fenton's reagent; tungstic acid, phosphotungstic acid, and metal ion catalyst salts in which the metal is iron (II), iron (III), copper (I), copper (II), chromium (III), chromium (VI), molybdenum, tungsten, and vanadium ions.
 14. The process of claim 9, wherein the step of contacting said hydrocarbon liquid components of the Process Mixture with ultrasound takes place at a space velocity in the range from 0.10 h⁻¹ and 10 h⁻¹.
 15. The process of claim 9, wherein the supported transition metal catalyst comprises: a porous inorganic oxide catalyst carrier and a transition metal catalyst, wherein the porous inorganic oxide catalyst carrier is at least one carrier selected from the group consisting of alumina, alumina/boria carrier, a carrier containing metal-containing aluminosilicate, alumina/phosphorus carrier, alumina/alkaline earth metal compound carrier, alumina/titania carrier and alumina/zirconia carrier, and wherein the transition metal catalyst is one or more metals selected from the group consisting of group 6, 8, 9 and 10 of the Periodic Table and wherein the Activating Gas mixture includes hydrogen gas and has an ideal gas partial pressure of hydrogen (p_(H2)) greater than 80% of the total pressure of the gas mixture (P).
 16. The process of claim 15, wherein the contacting the Feedstock Mixture with one or more supported transition metal catalysts under reactive conditions is selected from the group consisting of: a ratio of the quantity of the Activating Gas to the quantity of Feedstock Heavy Marine Fuel Oil in the range of 250 scf gas/bbl of Feedstock Heavy Marine Fuel Oil to 10,000 scf gas/bbl of Feedstock Heavy Marine Fuel Oil; a total pressure between of 250 psig and 3000 psig; an indicated temperature between of 500° F. to 900° F., and, wherein a liquid hourly space velocity is between 0.05 oil/hour/m³ catalyst and 1.0 oil/hour/m³ catalyst.
 17. A device for reducing the environmental contaminants in a Feedstock Heavy Marine Fuel Oil, the device comprising: means for contacting a Feedstock Heavy Marine Fuel Oil, wherein the Feedstock Heavy Marine Fuel Oil complies with ISO 8217 except for the environmental contaminates including a sulfur content (ISO 14596 or ISO 8754) greater than 0.50 wt %, with ultrasound having a frequency in the range of about 10 kHz and about 100 megahertz and a sonic energy in the range of about 30 watts/cm² to about 300 watts/cm², and a temperature ranging between 30° C. and 260° C. to give an ultrasonic pre-treated Feedstock Heavy Marine Fuel Oil; means for mixing a quantity of the ultrasonic pre-treated Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture; means for contacting the Feedstock Mixture with one or more catalysts under reactive conditions to form a Process Mixture from said Feedstock Mixture; means for receiving said Process Mixture and separating liquid components of the Process Mixture from any gaseous components and any by-product hydrocarbon components of the Process Mixture to form a Product Heavy Marine Fuel Oil and, means for discharging the Product Heavy Marine Fuel Oil.
 18. The device of claim 17, wherein the means for contacting a Feedstock Heavy Marine Fuel Oil with ultrasound comprises of a contacting vessel having a first feed inlet pipe through which the Feedstock Heavy Marine Fuel Oil is introduced into the contacting vessel; one or more industrial high energy ultrasound transducers optionally connected to an ultrasonic horn, located within the contacting vessel and positioned such that when the one or more industrial high energy ultrasound transducers are activated, ultrasound waves are induced into the in Feedstock Heavy Marine Fuel Oil resulting in ultrasonic desulfurization conditions, and an outlet pipe in fluid communication between the contacting vessel and means for mixing a quantity of the ultrasonic pre-treated Feedstock Heavy Marine Fuel Oil with a quantity of Activating Gas mixture to give a Feedstock Mixture.
 19. The device of claim 18, wherein the contacting vessel further comprises a second inlet for injecting aqueous solutions containing oxidizing agents into the Feedstock Heavy Marine Fuel Oil to form a mixture of aqueous solution and Feedstock Heavy Marine Fuel Oil upstream of the one or more industrial high energy ultrasound transducers and an outlet downstream of the one or more industrial high energy ultrasound transducers, said outlet being in fluid connection with both the contacting vessel and a separation vessel, wherein the separation vessel receives the mixture of aqueous solution and Feedstock Heavy Marine Fuel Oil after it has been subjected to ultrasound, wherein the separation vessel functions as a separation means to separate the ultrasonic pre-treated Feedstock Heavy Marine Fuel Oil from the aqueous solution.
 20. The device of claim 18 wherein the contacting vessel further comprises solid catalyst materials contained within the contacting vessel in the form of unsupported solid particles of catalyst materials, catalyst materials supported on pellets or particles, and screens coated or impregnated with the catalyst material, and wherein the catalyst materials are selected from the group consisting of from the group consisting of: Fenton's reagent; tungstic acid, phosphotungstic acid, and metal ion catalyst salts in which the metal is iron (II), iron (III), copper (I), copper (II), chromium (III), chromium (VI), molybdenum, tungsten, and vanadium ions. 